In the US, the weather is heating up. Most of the snow has already melted away and, as soon as we switch gears from Winter activities to Summer sports, we will all be sweating out of control. This is the time of the year when we lose ridiculous amounts of fluids and need to remember to replenish them.

Dehydration is the “silent performance killer.” It not only drastically inhibits our ability to put out power, but it can be deadly. To prevent it, it is necessary that we increase our fluids, carry more water bottles, carry hydration mix with us and stop more often to replenish liquids.

Yes, we’ve heard all this many times before. But do you actually know what fluids are best to hydrate with, and how to use them? Here are some hydration tips to help you perform your best this Summer.

PHOTO: Breckenridge

What is sweating?

Sweating is the physiological process of dissipating heat in response to an increase in our body’s core temperature. However, excessive sweating can result in a crucial loss of fluids and electrolytes. This may lead to dehydration, as well as a drastic decrease in our abilities to pedal a bike, plant our feet when we run, and focus in general.

What happens during dehydration?

When dehydration starts and it is not addressed, things get worse, fast. A chain of events begin to unfold: As you become dehydrated, your body experiences decreased blood volume, decreased cardiac output (your heart’s capacity to pump blood), and a decreased skin blood flow. These things decrease the rate you sweat, which in turn decreases your ability to dissipate heat, and ultimately results in a further increased core temperature.

Short answer: When you’re dehydrated, you get hotter and hotter until you overheat.

An Inside Look at Dehydration and Performance

In general exercise, you may not feel the effects of dehydration so drastically. Lose a mere 2% of body weight in sweat, and your performance will slightly decline.

Why do you need electrolytes?

When it comes dehydration, we don’t just lose body water, we also lose valuable electrolytes. Electrolytes are crucial for basically every muscle contraction that happens in the body. They control the neuro-electrical stimulation of muscle contractions and other important physiological processes during exercise.

Simply stated, if you lose electrolytes and don’t replace them, your muscles aren’t going to contract. This is why muscle cramping is one of the most common signs of dehydration.

There are four main types of electrolytes: Sodium, Chloride, Potassium and Magnesium. Sodium is probably the most important as it’s key for electrical activity and the contraction of muscles.

Average sodium loss per each liter of sweat is about 900 mg. During a three-hour race or training ride, you’ll lose approximately 3 liters (6.6 pounds) and 2,700mg of sodium.

Consider using a hydration mix to prevent your performance from being impacted negatively. Here are a few good options:

Lower than normal sodium levels results in a condition called hyponatremia. Along with decreasing your performance, this can also be dangerous and even life threatening in extreme conditions. Someone only drinking water will be at a clear performance disadvantage over someone who is replacing electrolytes correctly with a hydration mix.

PHOTO: Nuun Active, Trisports

Is it O.K. to just drink plain water?

In some very hot conditions, drinking too much plain water can be dangerous because it dilutes the electrolyte content (mainly sodium) in the blood. This exacerbates hyponatremia into a dangerous condition. Every year, too many athletes are admitted into hospitals after endurance events because they’re suffering from hyponatremia. A few have even died from water intoxication, which results when a person drinks too much water and dilutes the sodium content of their blood.

The Facts: When it comes to performance, the benefits of electrolyte fluid replacement versus plain water are loud and clear.

When exercising in hot environments, a recommendation of about 500-700 mg (0.5-0.7g) of sodium per each liter should be considered.

What to do when it’s really, really hot:

The simple answer: double up on your electrolytes. During extremely hot conditions, or if you’re the kind of person who sweats a lot, the electrolytes contained in a regular sports mix may not be enough to replace the amount of electrolytes lost in sweat. If this is the case, use extra electrolytes, or pre-load with drink mixes like Skratch Hyper Hydration (1700 mg of sodium), Osmo Pre-Load (1210 mg sodium) or The Right Stuff (1740 mg of sodium). These mixes have whopping doses of sodium and are meant to be used before super intense workouts or on very hot days. Make sure you test them out before a big event.

If you’re leery of using pre-loading drinks, just double up your electrolytes, and drink the double dose of sodium throughout your exercise. Add an extra scoop of Skratch, or drop in an extra tablet. This is usually what professional cyclists do at the Tour de France, and it works quite well.

What about carbs?

Fluid replacement is not just about fluids and electrolytes; it’s also about replacing carbs.

Carbs are energy. Without them, you bonk. It is very difficult to eat all the carbohydrates you need during a race or ride. For this reason, your sports drink is a great vehicle for carbohydrate delivery.

When should you drink?

You should always be drinking electrolytes. Drink throughout the day with low calorie hydration mix. Here are our recommendations:

For example, let’s say an athlete’s pre-ride weight is 70Kg (154Lbs) and post-ride weight is 66.5Kg (149Lbs). He consumed 1000mL (1L) fluids during his exercise and urinated one time (losing approximately 500mL). His ride duration was 4 hours.

His Fluid Deficit: 70Kg – 66.5Kg = 3.5Kg

His Total Sweat Loss: 3.5L+1L – 0.5L= 4L

His Sweat rate: 4L/4h= 1L/h

Your sweat rate will give you insight to how much fluids you are losing (per hour) when you exercise. To stay hydrated and perform your very best, make sure you are consuming enough to compensate for that loss.